Abrasive cut-off wheels



INVENTOR ATTORNEY W N W Whvmvwvm.

Dec. 31, 1968 P c DooLEY, JR

ABRASIVE CUT-OFF WHEELS Filed April 28, 1965 United States Patent O 3,418,762 ABRASIV E CUT-OFF WHEELS Peter C. Dooley, Jr., Lewiston, N.Y., assignor to The Carborundurn Company, Niagara Falls, N.Y., a corporation of Delaware Filed Apr. 28, 1965, Ser. No. 451,393 4 Clairns. (Cl. 51-206.5)

ABSTRACT OF THE DISCLOSURE An abrasive wheel having a body and a plurality of posts extending radially therefrom with abrasive segments disposed between adjacent posts. A pair of clamp shoes are engageable with each post and rockable therewith, respectively, and have beveled edges for embracing the complementary beveled edges of adjacent abrasive segments to secure the same onto the body of the wheel.

This invention relates to improvements in abrasive cutoff Wheels of the type having replaceable teeth.

Wheels of this Character, as used heretofore, are disclosed in Russ Patent No. 1,198,871, Sept. 19, 1916, and Cowie patent, No. l,894,087, Jan. 10, 1933. Such Wheels have used 'resn bonded abrasive segments, spaced at intervals around the periphery of a steel disc or 'body portion of the wheel to for-m a replaceable rim. 'These teeth or segments have been spaced widely apart, which has resulted in very short wheel life.

One object of this invention is to improve the construction of a cut-off wheel of the eharacter described by making it possible to obtain a more nearly complete abrasive periphery, at least approximately 90% complete, but with removable segments or teeth held securely to a central body portion.

Another object of the invention is to assure positive clamping of the abrasive segments or teeth to the body of the wheel and to provide for secure and efiective mounting of the teeth or segments thereon without any radial movement inward or outward with respect to the body portion. This -makes it possible to have wings or extensions on the segments which substantially close the peripheral gap that was provided heretofore by the clamping posts.

These objects may be accomplished, according to one embodiment of the invention, by mounting the segments or teeth between clamping means spaced apart circumferentially of the wheel. The clamping means is made up of one part, such as a post, secured to the body portion of the Wheel and cla-mping shoes adjustably secured to the posts and extending in embracing relation with the adjacent opposite edges of the segment or tooth. Each of the shoes has a heel portion formed thereon by an elongated rib in rocking engagement with the post, so that upon adjustment of the shoe, the adjacent edge of the segment or tooth is elamped securely thereto, the clamping force being exerted in a direction lying substantially in a transaxial plane cut through the axis of the body portion of the wheel.

This adjustment and clamping action occurs in a direction transversely of the Wheel without any radial movement of the adjusting means either inward or outward. This makes it possible to have wings or extensions on the segments which substantially closethe peripheral gap that would be provided between adjacent segments otherw1se.

This embodiment of the invention is illustrated in the accompanying drawings, in which:

FIG. 1 is a side elevation of a portion of an abrasive Wheel having the invention applied thereto; and

3,418,76Z Patented Dec. 31, 1968 'ice FIG. 2 is a cross section therethrough on the line 2-2 in FIG. 1.

In the embodiment shown in the drawings, the numeral 1 designates the center portion of the body of the wheel. This body portion 1 is usually provided with a hub for mounting on a drive shaft in the usual manuer of operating a cut-off wheel of the Character described.

Spaced at intervals around the periphery of the body portion 1 are abrasive segments or teeth, generally designated at 2. Such segments are usually made of fine grain abrasive material bonded by a suitable plastic, such as a resin, shellac or the like.

The mounting means for the abrasive segments or teeth 2 comprise radially extending posts 3 on the periphery of the body portion 1 and spaced apart circumferentially thereof. Each of the posts 3 preferably has bevelled lateral edges 4 converging inwardly toward the center of the wheel substantially in keystone shape, so as to overlap the adjacent side of a tapered edge 5 formed on the inner end portion 6 of the abrasive segment or tooth 2.

As Will 'be apparent from FIG. 1, the opposite edges of the inner end portion 6 of each abrasive segment eX- tend parallel with each other. These inner end portions of the segments preferably abut chord edges 7 formed on the periphery of the body portion 1 between the clamp posts 3.

The outer end portion of each abrasive segment 2 has lateral wings 8 extending in overlapping relation with the ends of the adjacent posts 3. In this way, the abrasive segments can be elongated so as to form a substantially continuous 'rm on the periphery of the wheel.

Each abrasive segment is secured in place between a pair of spaced posts 3 by shoes 9 disposed with their inner edges at the longitudinal center of the corresponding posts 3 and extending therefrom into overlapping clamping relation with the adjacent beveled edge 5 on the segment. The lateral edge of each shoe 9 is preferably beveled at 10 to conform to the bevel on the segment.

At its inner end, the clamping shoe is provided with an elongated rib 11 which is disposed in abutting and rocking relation with the adjacent side face of the post 3. A screw 12 extends loosely through each clamp shoe 9 into threaded engagement with the post 3 for adjusting the position of the clamp shoe transversely relative to the segment 2, thereby applying a lateral pressure against the bevelled edge 5 of the segment to secure the segment effectively to the center portion of the wheel. This means provides a positive clamping on the bevelled edge of the abrasive segment. The reaction of the clamping force of the screw 12 comes between the heel provided by the raised rib 11 and the clamping face 10 bearing laterally against the bevelled edge 5 of the segment.

By placing the actual center of the clamping screw 12 below its theoretical position, a radial inward movement of the shoe and thereby of the segment will result, giving a very positive wedging action on the abrasive segment, tending to seat it against the chord 7 on the periphery of the center portion of the wheel.

The cross section of the clamping plate forming the shoe 9 is thin enough so that the clamping force of the screw 12 will deform it within its elastic limit to provide a looking effect and reduce the likelihood of the fastening means becoming loosened due to the vibration resulting from the Cutting action.

The abrasive segment 2 can be inserted into its slot between circumferentially spaced posts 3 Without any radial -movement inward or outward of the locking means. Thus, it is possible to provide the wings or extensions indicated at 8 on the respective segments which substantially close the peripheral gap required heretofore by the clamp posts then used.

Since these wings or extensions 8 on the outer portions of the segment would become very weak cantilever sections as the wheel Wears down, this construction provides for curving these extensions into the center portion 6 of the segment, so that the leading and trailing edges of each segment lrecede toward the center of the segment as the latter wears. The present device makes it possible to obtain about a 90% complete abrasive periphery on a cut-off wheel of this Character having removable segments or teeth and yet these segments or teeth are securely clamped in place during operation.

While-the invention has been illustrated and described in one embodiment, it is recognized that variations and changes 'may be made therein Without departing from the invention as set forth in the claims.

I claim:

1. An abrasive cut-off wheel eomprising a central body portion having radially extending clamping posts thereon and spaced apart circumferentially; said central body having an axis; abrasive saw teeth between adjaeent posts; each of said teeth having opposite tapered edges toward adjacent posts in overlapped relation therewith and outer Wing portions thereon extending circumeferentially of the Wheel overlapping the outer ends of the posts; said teeth having curved segments between said Wing portions and said opposite tapered edge portions; and means secured to each of said posts for exerting a clamping force on said tapered edges in a direction lying substantially in a transaxial plane cut through the axis of said body.

2. An abrasive cut'off Wheel as defined in claim 1 wherein said last-mentioned means comprises a pair of shoes rockably mounted on each of said posts and having outer edges in overlapping engagement with said opposite tapered edges of said teeth.

3. An abrasive cut-off Wheel as defined in clai-m 2 including means for adjusting the clamping force exerted by the shoes on said teeth.

4. An abrasive cut-off wheel as defined in claim 3 wherein said shoes have ribs along their inner edges, respectively, in rocking relation with said post.

References Cited UNITED STATES PATENTS 1,198,87l 9/1916 Russ 125 22 1,502,697 7/1924 Tone 51 206.5 1,697,505 1/1929 Hyde 51-2065 1,783,727 12/1930 Larsson 51--206.5

ROBERT C. RIORDON, Primary Examner.

D. G. KELLY, Assistant Examner.

U.S. Cl. X.R. 125-22 

